testcases/regress/smc.c

   1 #include <stdio.h>
   2
   3 /*
   4  * Test self-modifying code
   5  */
   6
   7 volatile int array[20];
   8
   9 int return_const(short *p, int i)
  10 {
  11     // Include lots of writes to stress store buffer flushing
  12     array[0] = i;
  13     array[1] = i;
  14     array[2] = i;
  15     array[3] = i;
  16     array[4] = i;
  17     array[5] = i;
  18     array[6] = i;
  19     array[7] = i;
  20     array[8] = i;
  21     array[9] = i;
  22     array[10] = i;
  23     array[11] = i;
  24     array[12] = i;
  25     array[13] = i;
  26     array[14] = i;
  27     array[15] = i;
  28     array[16] = i;
  29     array[17] = i;
  30     array[18] = i;
  31     array[19] = i;
  32     *p = i;
  33
  34     //__builtin_flush_icache(p, 2);
  35
  36     // calling __builtin_flush_icache(p, 2) is correct, but here
  37     // I use synci directly to test the worst case.
  38     asm(".set push;"
  39         ".set mips32r2;"
  40         "synci %0;"
  41         ".set pop" :: "m" (*p));
  42
  43     asm(".set noreorder");
  44     asm("li $2, 1729");
  45     asm("jr $31");
  46     asm("nop");
  47     asm(".set reorder");
  48 }
  49
  50 int return_const2(short *p, int i)
  51 {
  52     // Include lots of writes to stress store buffer flushing
  53     array[0] = i;
  54     array[1] = i;
  55     array[2] = i;
  56     array[3] = i;
  57     array[4] = i;
  58     array[5] = i;
  59     array[6] = i;
  60     array[7] = i;
  61     array[8] = i;
  62     array[9] = i;
  63     array[10] = i;
  64     array[11] = i;
  65     array[12] = i;
  66     array[13] = i;
  67     array[14] = i;
  68     array[15] = i;
  69     array[16] = i;
  70     array[17] = i;
  71     array[18] = i;
  72     array[19] = i;
  73     *p = i;
  74
  75     //__builtin_flush_icache(p, 2);
  76
  77     // calling __builtin_flush_icache(p, 2) is correct, but here
  78     // I use synci directly to test the worst case.
  79     asm(".set push;"
  80         ".set mips32r2;"
  81         ".set noreorder;"
  82         "b here;"
  83         "synci %0" :: "m" (*p));
  84
  85     asm("loop: b loop");
  86
  87     asm("here: li $2, 1729");
  88     asm("jr $31");
  89     asm("nop");
  90     asm(".set pop");
  91 }
  92
  93 int main()
  94 {
  95     int i;
  96
  97     for (i = 0; i < 100; ++i) {
  98         short *p = (short *) return_const2 + 53; // Magic!
  99         if (return_const2(p, i) != i) {
 100             printf("Failure\n");
 101             return 1;
 102         }
 103     }
 104
 105     printf("Success\n");
 106
 107     return 0;
 108 }